Method Improvement And New Functions Implement On Reliability Analysis For Distribution Systems

This paper improves the method on reliability analysis for distribution systems and meliorates the reliability analysis module in"Computer Decision-making Support System for Urban Power Distribution Network Planning CNP40". Main works of this paper are as follows:1. Improvements are made on the models and methods of reliability analysis in CNP40, including: a) A power source model is added on reliability calculation for distribution systems and the reliability algrithm are updated based on the new model. The new algorithm considers the influence of the failure rate of higher level power source on reliability. b) Because there are lots of customers owning more than one distribution transformer, a customer model on reliability calculation for distribution systems are set up. Case study results comparison has showen that method in this paper is more actual compared with traditional one that makes distribution transformers as unit for calculation and statistic. c) The former CNP40 system considers equivalent point as a simple point, and it does not consider the inside configuration of a equivalent point, and treats it as one distribution transformer.This approach causes errors in reliability result. To solve the problem, this paper proposes a modified method on equivalent point processing with more accurate result. All the methods above have been implemented and tested in CNP40 system.2. This paper develops some new functions based on the former reliability module in CNP40, including: a) New implements on reliability calculation has taken equipment maintenance into consideration, while the old version only considers equipment fault. This new approach has made the software more practical; b) A new function has implemented to invoke topological algorithm programm intelligently before reliability calculation, which improves the calculation speed and makes it more convenient for users. c) Reliability calculation on partial electric network is developed to improve the efficiency of reliability analysis.